Tobacco slab

ABSTRACT

The invention relates to a continuous tobacco slab ( 10 ) made of shredded tobacco which slab has a substantially uniform composition and a substantially uniform distribution of the shredded tobacco. The invention further relates to a multi-layer structure comprising the tobacco slab and in addition at least one layer, preferably one or two layers, of a smokable material other than shredded tobacco. Furthermore, the invention provides a package comprising the tobacco slab or multi-layer structure.

The present invention relates to a tobacco slab, a process for makingsuch tobacco slab and a package comprising such tobacco slab.

Pre-formed pieces of tobacco are known in the art. For example, U.S.Pat. No. 1,365,969 discloses a plug of tobacco for chewing or pipesmoking. The plug is composed of a densely compacted filler of‘long-cut’ tobacco enclosed in leaf tobacco wrapper. For use, sectionsor slices of tobacco are broken or cut off from the plug and manuallybrought into a sufficiently ‘fluffy’ condition suited for chewing orsmoking. A disadvantage of the disclosed tobacco plug is that thetobacco is very densely compressed and requires manual manipulationbefore use.

EP-A-0 647 411 discloses a tobacco cuboid made of several pre-definedsub-portions. The tobacco cuboid is for a smoker's use to make his owncigarettes. The individual sub-portions are separated either bymechanical means, for example by cuts or grooves, or by separating websmade of a non-smokable material. The cuboid is made from a tobaccostrand which is then cut into partial strands corresponding to thesub-portions. The coherence among the sub-portions is problematical.

DE-A-10346649 discloses tobacco portions made from a non-woven fabriccontaining at least 50 percent of tobacco. The non-woven fabric is acoherent, self-supporting web.

There is an increasing trend among smokers towards roll-your-own andmake-your-own cigarettes. Roll-your-own cigarettes are made using finecut tobacco which has a density in the range of about 60 mg/cm³ and istypically sold in reclosable, flexible plastic pouches. One of thedisadvantages of the roll-your-own method is that it allows forcigarettes of variable tar and nicotine content. Make-your-own methodsaim at overcoming this disadvantage by relying on pre-made orpre-defined tobacco portions which are transferred into pre-made tubesof cigarette paper, typically with a filter.

It is an object of the present invention to provide an improved tobaccomaterial which can be used by a smoker to make his own cigarettes.

The present invention provides a continuous slab of smokable tobaccowith a substantially uniform composition and distribution of shreddedtobacco throughout the slab. In particular, the present inventionprovides a tobacco slab made of shredded tobacco characterized in thatit is continuous and has a substantially uniform composition and asubstantially uniform distribution of the shredded tobacco. As usedherein, shredded tobacco includes cut tobacco. The tobacco slab of theinvention enables the consumer to make his own cigarettes of consistentquality and smoking behavior.

The tobacco slab of the invention is obtainable by a process comprisingthe steps of filling a pre-defined amount of shredded tobacco into asuitable mold, evenly distributing the shredded tobacco in the mold andevenly compressing the shredded tobacco. Preferably, such processfurther comprises the steps of removing the slab from the mold andtransferring the slab into a package.

The slab according to the present invention is a continuous tobaccoslab. The slab lacks any means or indications of pre-portioning orseparation. In particular, the slab is devoid of any mechanical orphysical means creating pre-portions, such as, for example, grooves,cuts or separating webs.

The tobacco slab according to the present invention is composed ofshredded tobacco, preferably in cut filler form, for example blended,cased, cut and flavored tobacco. Preferably, the slab has a thickness ofbetween about 6 mm and about 12 mm. The slab has a substantially uniformand homogeneous composition. This facilitates the production of auniform batch of self-made cigarettes with substantially consistentquality and smoking behavior under identical conditions.

The tobacco slab may comprise any desired quantity of shredded tobaccosufficient to make at least two cigarettes. Preferably, the tobacco slabof the invention comprises at least about 3.5 g of cut filler, morepreferably at least about 15 g of cut filler, most preferably betweenabout 15 g and about 50 g of cut filler, which amount is evenlydistributed across and throughout the slab. If desired, the cut fillermay comprise small amounts of one or more suitable non-tobaccoadditives, for example suitable particulate additives. Suitableadditives are known in the art and have been disclosed for incorporationin the cut filler used in the tobacco rod of pre-manufacturedcigarettes. Such additives include, for example, additives, such asnanoparticle additives, which during smoking of the cigarette arecapable of acting as oxidants for the conversion of carbon monoxide tocarbon dioxide or as catalysts for the conversion of hydrocarbons,aldehydes, or phenolic compounds to carbon dioxide and water.

The shredded tobacco is substantially uniformly distributed across theslab. The tobacco density is a function of tobacco weight andcompression. As compared to loose cut filler, the cut filler in the slabis moderately compressed, that is the tobacco essentially retains itsnatural flexibility and elasticity after compression. Preferably, thecut filler in the slab is uniformly compressed by a factor of betweenabout 2 and about 6, more preferably by a factor between about 2 andabout 4, most preferably by a factor of between about 3 and about 4 ascompared to loose cut filler of the same composition. The compressionfactor is essentially the same across and throughout the cut filler.Preferably, the cut filler in the slab has an average (filling) densitybetween about 150 mg/cm³ and about 250 mg/cm³. The average fillingdensity of the slab is calculated as the quotient of weight per volume.The person of ordinary skill in the art will readily appreciate that thedensity will be affected by various parameters, including for examplethe type or types of tobacco and the amount of expanded tobacco employedin the cut filler. Preferably, the tobacco slab of the present inventionhas substantially the same firmness across the slab.

The strand length or cutting width of the shredded tobacco in thetobacco slab of the present invention is relatively short andsubstantially the same as in conventional pre-fabricated cigarettes, forexample between about 0.4 mm and about 0.9 mm. Preferably, the cuttingwidth of the cut filler is between about 0.6 mm and about 0.8 mm.

Preferably, the tobacco slab according to the present invention does notinclude any outer or inner binding agent such as, for example,combustible fibers like cellulose or other natural materials woven intothe tobacco, agar agar, guar gum or cellulose pulp.

The continuous tobacco slab of the present invention is of pre-definedshape and size. Preferably, shape and size are such that the slab yieldsat least two, preferably at least five, more preferably between 20 and40 cigarettes of a standard length and diameter, for exampleconventional king size. Typically, the dimensional parameters of thefinal cigarette, and hence of the slab, will be determined by the sizeof the commercially available, pre-manufactured cigarette paper tubes.In particular, height and width of the slab are such that the consumercan readily make his own cigarettes, for example conventional king sizefilter cigarettes, relying on commercially available cigarette papertubes. To minimize or avoid tobacco waste, the width of the slabessentially corresponds to the length of such tubes (excluding thefilter). If desired, the width of the slab may slightly exceed thefilling length of the tubes by up to about 10 percent, or less. Whilethe tobacco slab may be of any shape, the shape should be such as tominimize waste in use, for example on a cigarette making device.Preferably, the slab has the shape of a rectangular parallelepiped witha height of between about 6 mm and about 12 mm, preferably of betweenabout 8 mm and about 12 mm. Preferably, the slab width is between about65 mm and about 80 mm. The slab length is not crucial and may varydepending on the number of lo cigarettes the block is intended to yield.Advantageously, the slab length is between about 75 mm and about 200 mm.The maximum slab length may favorably be matched with the design of thecigarette making device, which the smoker may use to produce self madecigarettes using the tobacco slab of the is present invention. To avoidcigarettes with loose ends, the tobacco slab does not flatten towardsits edges.

If desired, the slab may be designed such that its height or its cutfiller density, or both, are slightly increased along one or morepre-defined edges, preferably along the two edges determining the slabwidth. The increased height and/or density along at least onepre-defined edge may serve to facilitate transfer of the slab, forexample into the package or, in particular, transfer into and through acigarette making device. Preferably, the density is suitably increasedalong one side surface while the slab height is kept constant across theslab.

In a preferred aspect, the present invention provides a tobacco slabessentially consisting of shredded tobacco, preferably in cut fillerform. Preferably, the tobacco slab has a density of between about 200mg/cm³ and about 250 mg/cm³, more preferably between about 220 mg/cm³and about 240 mg/cm³. Advantageously, the total water content of theslab is between about 12 and about 16 percent. Preferably, the cutfiller does not comprise any non-tobacco particulate additives.Preferred is such tobacco slab consisting of cut filler which slab hasone or more of the features indicated herein as being preferred.

Such tobacco slab may be made using a mold comprising a bottom (or top)wall and four side walls. The plan of the mold substantially correspondsto the plan of the tobacco slab to be produced. Advantageously, moldlength and width are slightly smaller, for example less than a fewmillimeters smaller, than width and length of the desired slab. The sidewalls of the mold must be high (deep) enough so that the mold canreadily accommodate the chosen amount of loose cut filler. For example,the mold should be about 4 to about 5 times higher, than the desiredheight of the slab. The mold may be made of any suitable material, suchas steel. To facilitate removal of the slab from the mold, for exampleby pushing, the mold is preferably made of or coated with a materialwhich does not stick to cut tobacco, for example a suitable plasticmaterial, and which is approved for use with food. The mold is uniformlyfilled with the desired amount of cut tobacco. Subsequently, the cutfiller in the mold is evenly compressed by application of apre-determined external pressure to yield a tobacco slab of pre-definedshape and dimensions. The external pressure may be applied,simultaneously or successively, to one or more surfaces of the slab.Suitable compression tools and methods are readily known in the art. Forexample, a pre-defined pressure may be exerted by means of a rigid platewhich may be moved mechanically or pneumatically. Preferably,compression is such that the height of the compressed slab is about 1 to3 mm less than the desired final height of the slab. Immediately afterthe pressure has been released the slab is transferred into a suitablepackage as described herein below. Preferably, this transfer involvessliding and/or pushing the slab by mechanical means. The transfer isperformed such that the geometrical shape and the integrity of thetobacco slab including its density, uniformity and distribution aresubstantially maintained. Advantageously, the mold may have one or tworemovable side walls to facilitate pushing and sliding the slab out ofthe mold. Alternatively, the mold may have a bottom wall which can besuitably raised or lowered to facilitate transfer of the slab out of themold. In the package, the slab may slightly expand until it fills theavailable pack volume assuming its desired final dimensions.

Alternatively to the above described sequential process, the slabsaccording to the invention may also be made in a continuous process, forexample, by cutting slabs of the desired size from a continuous strand.

The tobacco slab obtainable according to the process of the invention isnot a self-supporting non-woven fabric as disclosed in DE-A-10346649.But the present invention provides a tobacco slab made of shreddedtobacco characterized in that it is continuous and has a substantiallyuniform composition and a substantially uniform distribution of theshredded tobacco which slab is obtainable by a process comprising thesteps of filling a pre-defined amount of shredded tobacco into a mold,evenly distributing the shredded tobacco within the mold and evenlycompressing the shredded tobacco by exertion of a pre-defined pressureand which slab excludes a self-supporting non-woven fabric. The tobaccoslab as provided herein is a non-self supporting structure which loosesits dimensional integrity and stability without proper support. Meanssupporting the slab are essential during its manufacture,transportation, storage and handling. In particular, the slab has verylittle tensile strength.

A method suitable to determine that a given slab is not self-supportingand thus a tobacco slab according to the invention is a ‘lifting test’.The test involves a tobacco slab made of 23 g of cut filler having awidth of 73 mm, a height of 11 mm and a length 144 mm. The slab iscarefully removed from its package, transferred onto a flat support,such as a table, and lifted with only two fingers. No other supportingmeans for the slab is involved during the lifting. For example, the slabmay be taken up and lifted from a supporting surface by partially orentirely covering the right and left side surfaces (corresponding to theslab width) with the index fingers of each hand. Alternatively, the slabmay be seized between the thumb and the index finger of the same handand lifted. On exposure to such test a non-self-supporting tobacco slabaccording to the invention will loose its dimensional integrity, that isit will break and fall apart.

In another preferred aspect, the present invention provides amulti-layer structure comprising a tobacco slab according to theinvention and in addition at least one layer, preferably two layers, ofanother suitable smokable material approved for use in cigarettes. Forexample, such suitable smokable materials include paper made of naturalfibers, for example tobacco fibers, and reconstituted tobacco sheet. Apreferred material is top loaded reconstituted tobacco sheet. Suchmaterial is known in the art and may be made as described inWO-A-03/082030. Preferred is such multi-layer structure comprising atleast one layer of another smokable material. Advantageously, such atleast one layer forms an outer surface of the multi-layer structureproviding for a relatively smooth outer surface of the structure andreducing sliding friction and/or static (sticking) friction as comparedto the out surface of the tobacco slab. Such layer thus facilitatestransfer of the structure, for example into or out of the pack.Advantageously, the layer or layers self-adhere to the tobacco slabwithout additive. The features of the slab indicated above, inparticular those described as preferred and in particular those ofweight, width, length and average density, also apply for suchmulti-layer structures. While the multi-layer structure provided hereinmay or may not be self-supporting, the tobacco slab component of suchstructure is not self-supporting.

A preferred embodiment has a sandwich type, multilayer structure, morepreferably a three layer structure. Most preferably, such three layerstructure is a symmetrical structure wherein the top layer is made ofthe same material as the base layer. Particularly preferred is a tobaccostructure which is composed of a base layer of smokable material (otherthan solely cut filler), a middle layer of cut filler (i.e. of a tobaccoslab according to the invention) and a top layer of smokable material(other than solely cut filler). Typically, the front, the back and theside surfaces of the cut filler middle layer are not covered or enclosedby the other smokable material used in another layer of a multi-layerstructure. Advantageously, the base and top layers are each made of thesame smokable material, preferably reconstituted tobacco sheet, morepreferably top loaded reconstituted tobacco sheet. In the latterembodiment, the cut filler top loads advantageously face towards the cutfiller middle layer. The top and base layers each have a thickness ofabout 0.5 mm to about 2 mm while the cut filler middle layer has athickness of about 6 mm to about 10 mm.

Typically, the amount of reconstituted tobacco comprised in the tobaccoslab or the multi-layer structure according to the invention (in sheetform and/or in the cut filler) is limited. The total amount ofreconstituted tobacco must not exceed the upper limit as defined in theapplicable regulatory standard.

A multi-layer structure comprising the tobacco slab and at least onelayer, preferably two layers, of another suitable smokable material maybe produced using the tools and methods as described above. For example,to produce a three layer tobacco structure as described above the bottomof a suitable mold, such as a mold as described above, is laid out witha sheet of reconstituted tobacco. Advantageously, the size of the sheetis such that it covers the entire surface of the mold bottom.Subsequently, the mold is filled with a defined amount of cut filler asdescribed above. After covering the cut filler layer with another sheetof reconstituted tobacco, a defined pressure is applied to yield atobacco structure with a compression factor and cut filler density whichis slightly higher than the compression factor and density desired forthe final multi-layer structure.

In yet another aspect, the present invention provides a packagecomprising the continuous tobacco slab or the multi-layer structure ofthe invention. In the following the slab and the multi-layer structureare referred to as the “product”. Such pack may be made of any suitablematerial or combination of materials, including, for example but notlimited to carton, cardboard, metal or plastic. Preferably, the packageis a rigid pack which tightly encloses the product. The rigid pack ofthe invention may be composed of one, two or more parts. The pack has apre-defined three-dimensional shape which is selected such as to matchand support the final three-dimensional shape of the product. Anappropriate shape and sufficient rigidity of the pack are essential toretain crucial product properties, including shape, dimension anddensity of the tobacco product, in particular the tobacco slab. Thismeans that the packaged product should substantially retain its shape,dimension and density during all further manipulation until consumptionincluding transportation and storage. For example, a cardboard pack witha grammage of between about 220 g/m² and 300 g/m² is sufficiently rigid.Advantageously, one or more of the pack surfaces facing the tobaccoproduct are partially or fully coated with a material which is approvedfor use with food and suitable to reduce or minimize friction uponremoval or insertion of the product. Furthermore, the package willsupport the freshness of the tobacco product and prevent its drying out.Particularly preferred is a pack made of cardboard whose inner surfacesare completely coated with aluminum foil.

While size and shape of the pack may be such to accommodate more thanone tobacco product, preferred is a pack containing one piece ofproduct.

A preferred pack of the invention is a slide and shell type pack whichcomprises an inner sleeve and an outer sleeve. The inner sleeve directlycircumscribes or encloses the tobacco product. Preferably, the innersleeve is designed such that it covers four outer surfaces of theproduct including the two major outer surfaces of the product, inparticular its top, bottom, front and rear surfaces. The front and rearsurfaces are determined by the product length. The two side surfaces ofthe product (determined by the product width) are not covered by theinner sleeve. Preferably, the outer sleeve is designed such that itdirectly circumscribes the inner sleeve with the tobacco product andcovers the two product side surfaces which are not covered by the innersleeve. Preferably, the outer sleeve covers the side surfaces determinedby the product width and the top and the bottom surfaces of the innersleeve. In use, the consumer removes the outer sleeve by pushing theinner sleeve circumscribing the tobacco product out of the outer sleeve.Preferably, the outer and the inner sleeve are both made from rigidcardboard. If desired, the inner surfaces of the sleeves, in particularthe inner surface of the inner sleeve, may be partially or entirelycoated with another material or metallized suitable to reduce friction.Suitable coating materials are readily known in the art and includethose disclosed for use in cigarette paper tubes. A particularlypreferred pack according to the invention is a slide and shell packwherein the inner and outer sleeves are made of aluminum laminatedcardboard with a total grammage in the range of between about 220 g/m²and about 300 g/m², for example with a total grammage of 275 g/m² (250g/m² for the cardboard; 25 g/m² aluminum foil). Reduction of frictionfacilitates the removal of the outer sleeve or pushing the tobaccoproduct out of the inner sleeve without breakage. Preferably thedimensions of the inner sleeve correspond to the desired productdimensions. Optionally, the package may comprise an inner frame.

Advantageously, the package further comprises an outer wrapper topreserve freshness of the tobacco product and prevent drying out.Suitable wrappers are known in the industry and include wrappers frommaterials which are currently used to wrap cigarette packs or cartons,such as polypropylene. The outer wrapper may include means facilitatingits removal, such as a tear tape.

In yet another aspect, the present invention provides a containerdesigned to hold several, for example up to ten, packs comprising atobacco product according to the present invention.

To make his own cigarettes starting from a continuous tobacco product ofthe invention, the consumer may use a cigarette making device tofacilitate transferring a suitably sized piece of the slab or themulti-layer structure into a pre-made cigarette tube. Optionally, suchtube comprises a filter, preferably a ventilated filter.

For example, a device suitable for use with the tobacco slab ormultilayer structure according to the present invention comprises aportioning means, a separating means such as a knife suitable toseparate a portion of tobacco from the slab or multi-layer structure, atransportation means to move the slab or multilayer structure towardsthe separating means by a defined distance and a filling means to fillthe portion into the pre-made cigarette tube. During this procedure themaking device, the pack or both support the integrity of the tobaccoslab or multi-layer structure during the process. Advantageously, thepack comprising the tobacco product is inserted in the cigarette makingdevice. In use, the tobacco product is moved out of the pack portion byportion. Since the tobacco slab according to the invention has asubstantially uniform tobacco density across the whole volume of theblock, each portion of the same size contains substantially the sameamount of tobacco.

Embodiments of the invention will now be described, by way of exampleonly, and with reference to the accompanying drawings, in which:

FIG. 1 shows a continuous tobacco-slab 10 consisting of one layer of cutfiller;

FIG. 2 shows a continuous three-layer sandwich structure 20 wherein thebase layer 12 and the top layer 14 layer each are a sheet ofreconstituted tobacco, and the middle layer is a tobacco slab 10 of cutfiller.

The continuous tobacco slab 10 in FIG. 1 shows a continuous tobacco slab10 of the invention consisting of a single layer of cut filler. The slab10 has a width of 73 mm, a height of 8 mm and a length of 140 mm. It ismade of 24 g of cut filler and has an average filling density of about235 mg/cm³. The slab may yield at least 30 cigarettes. The cutting widthof the cut filler is 0.65 mm.

The continuous sandwich structure 20 in FIG. 2 has three layers andconsists of a 0.5 mm base layer 12 made of top loaded reconstitutedtobacco sheet, a 9 mm tobacco slab 10 made of cut filler and a 0.5 mmtop layer 14 of top loaded reconstituted tobacco sheet. The cut fillertop loads of the base layer 12 and the top layer 14 each face towardsthe cut filler middle layer 10. The weight of the structure is 24 g, theaverage density is about 240 mg/cm³.

1. A continuous tobacco slab made of shredded tobacco obtainable by aprocess comprising the steps of filling a pre-defined amount of shreddedtobacco into a mold, evenly distributing the shredded tobacco within themold and evenly compressing the shredded tobacco by exertion of apre-defined pressure.
 2. The tobacco slab according to claim 1 whereinthe shredded tobacco is in cut filler form.
 3. The tobacco slabaccording to claim 1 which has an average density of between about 150mg/cm³ and about 250 mg/cm³.
 4. The tobacco slab according to claim 1which has a width of between about 65 mm and about 80 mm.
 5. Amulti-layer structure comprising a tobacco slab according to claim 1 andin addition at least one layer, preferably one or two layers, of asmokable material other than shredded tobacco which multi-layerstructure is obtainable by the process of claim 1 comprising theadditional step of adding at least one layer of smokable material otherthan shredded tobacco into the mold before and/or after filling thepre-defined amount of shredded tobacco into the mold.
 6. The multi-layerstructure according to claim 5 which has an average density of betweenabout 150 mg/cm³ and about 250 mg/cm³.
 7. The multi-layer structureaccording to claim 5 which has a width of between about 65 mm and about80 mm.
 8. The multi-layer structure according to claim 5 which has athree layer structure wherein the base layer and the top layer eachconsist of reconstituted tobacco sheet, preferably top loadedreconstituted tobacco sheet, and the middle layer essentially consistsof cut filler.
 9. The tobacco slab according to claim 1 or themulti-layer structure according to claim 5 wherein the cut fillerdensity is slightly higher along one or more, preferably two pre-definededges.
 10. A process for making a tobacco slab made of shredded tobaccocharacterized in that it is continuous and has a substantially uniformcomposition and a substantially uniform distribution of the shreddedtobacco or a multi-layer structure comprising the tobacco slab and inaddition at least one layer, preferably one or two layers, of a smokablematerial other than shredded tobacco, said process comprising the stepsof filling a pre-defined amount of shredded tobacco into a mold, evenlydistributing the shredded tobacco within the mold, optionally adding atleast one layer of smokable material other than shredded tobacco intothe mold before and/or after filling a pre-defined amount of shreddedtobacco into the mold, evenly compressing the shredded tobacco andoptionally the at least one additional layer by exertion of apre-defined pressure, and removing the slab or the multi-layer structurefrom the mold, and optionally transferring the slab or the multi-layerstructure into a package.
 11. A package comprising the tobacco slabaccording to claim 1 or the multi-layer structure according to claim 5.12. The package according to claim 11 which comprises an inner sleeveenclosing the tobacco slab or the multi-layer structure and an outersleeve enclosing the inner sleeve.
 13. A package comprising a tobaccoslab made of shredded tobacco which slab is continuous and has asubstantially uniform composition and a substantially uniformdistribution of the shredded tobacco, said package being characterizedin that it has a pre-defined three-dimensional shape.
 14. Use of thetobacco slab according to claim 1 or the multi-layer structure accordingto claim 5 in a cigarette making device for the preparation of make yourown cigarettes.
 15. Use of the tobacco slab according to claim 1 or themulti-layer structure according to claim 5 wherein the tobacco slab orthe multi-layer structure is partially enclosed by a package.